Melting Ice Floods Greenland River, Satellite Photo Shows

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Melting ice in Greenland has swelled the island's rivers with
water. A NASA satellite snapped a photo of meltwater overflowing
the banks of the Watson River near Kangerlussuaq, a key air
transportation hub, on July 12.

Two weeks later, however, river levels have receded somewhat,
according to a release from the NASA Earth Observatory.

"Water rises every year, but I've never before observed it at
this level of discharge," said Richard Forster, a University of
Utah researcher who has done extensive fieldwork in Greenland, in
a statement. "It was also about two weeks prior to the normal
seasonal peak."

The town, known as Kanger, hosts one of the island's busiest
commercial airports and is a frequent departure point for
scientific research flights. It lies about 74 miles (125
kilometers) from the sea.

The water most likely came from melting of the ice sheet — rather
than an ice-dammed lake bursting or glacial lake drainage — as
the high discharge was maintained for so long, Forster said.

This year's ice melt is well above average: About half of
Greenland's surface ice tends to melt every summer, with the
meltwater at higher elevations quickly refreezing in place and
the coastal meltwater either pooling on top of the ice or
draining into the sea. [ Giant
Ice: Photos of Greenland's Glaciers ]

The massive melt may have been caused by a ridge or dome of warm
air hovering over Greenland.

Signs of ice melt were even found around Summit Station in
central Greenland, which at 2 miles (3.2 kilometers) above sea
level is near to the highest point on the ice sheet.

The melting characteristics of such a huge ice sheet — spanning
656,000 square miles (1.7 million square kilometers) — is
important for various reasons, particularly its potential effect
on sea levels. If melted completely, the Greenland ice sheet
could contribute 23 feet (7 meters) to global
sea-level rise, according to a 2007 report by the
Intergovernmental Panel on Climate Change, the international body
charged with assessing climate change.

Whether or not this recent massive melt will affect the overall
ice loss this summer, and as such bump up sea level, is still an
open question.

In other Greenland-melting news, a massive iceberg that recently
broke away from one of Greenland's largest glaciers is making its
way downstream and toward the open ocean, as shown by
a new satellite photo.

The drifting island of ice split from the Petermann Glacier's ice
shelf — the front end of a glacier, which hangs off the land and
floats on the ocean.

The newly
birthed berg is estimated to be about 46 square miles (120
square kilometers), and finally broke away from the floating
tongue of ice on Monday, July 16.